• Title/Summary/Keyword: critical criteria

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Study on Plugging Criteria for Thru-wall Axial Crack in Roll Transition Zone of Steam Generator Tube (증기발생기 전열관 확관천이부위 축방향 관통균열의 관막음 기준에 관한 연구)

  • Park, Myeong-Gyu;Kim, Yeong-Jong;Jeon, Jang-Hwan;Kim, Jong-Min;Park, Jun-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.9
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    • pp.2894-2900
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    • 1996
  • The stream generator tubes represent an integral part of a major barrier against the fission product release to the environment. So, the rupture of these tubes could permit flow of reactor coolant into the secondary system and injure the safety of reactor coolant system. Therefore, if the crack was detected during In-Service Inspection of tubes the cracked tube should be evaluated by the pulgging criteria and plugged or not. In this study, the fracture mechanics evaluation is carried out on the thru-wall axial crack due to Primary Water Stress Corrosion Cracking in the roll transition aone of steam generator tube to help the assurence the integrity of tubes and estabilish the plugging criteria. Due to the Inconel which is used as tube material is more ductile than others, the plastic instability repture theory was used to calculate the critical and allowable crack length. Based on Leak Before Break concept the leak rate for the critical crack length and the allowable leak rate are compared and the safety of tubes was given.

A Study on the Development and Application of Korean Medical Critical Pathway of Childhood Anorexia (소아 식욕부진의 한의표준임상경로 개발 및 시범 적용 연구)

  • Choi Seo Yeon;Jeong Yoon Kyoung;Bang Miran;Chang Gyu Tae
    • The Journal of Pediatrics of Korean Medicine
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    • v.37 no.3
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    • pp.1-16
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    • 2023
  • Objectives We aimed to investigate the effectiveness of the Korean medical critical pathway (CP) in treating childhood anorexia. Methods In total, 21 patients who met the criteria and agreed to provide information were assigned to the CP group, while 24 patients who met the criteria, agreed to provide information, but disagreed with CP application were assigned to the non-CP group. Demographic, clinical, and economic indices were compared between the two groups. Clinical indices before and after treatment were also compared between the two groups. Results In the CP group, height, weight, body mass index (BMI), BMI percentile, and food approach (FAP) increased significantly after treatment, and numeric rating scale (NRS) and food avoidance (FAV) scores decreased significantly. In the non-CP group, height, weight, weight percentile, BMI, BMI percentile, and FAP increased significantly, whereas NRS and FAV decreased significantly after treatment. Compared to the non-CP group, CP application increased FAP and decreased FAV, medical expenses per consultation, and the total treatment period. Conclusions The application of the Korean medical critical pathway for childhood anorexia is an effective cure system that decreases overall medical expenses with good-quality treatment by means of the standardization of medical practices.

Advanced approach to information security management system utilizing maturity models in critical infrastructure

  • You, Youngin;Oh, Junhyoung;Kim, Sooheon;Lee, Kyungho
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.10
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    • pp.4995-5014
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    • 2018
  • As the area covered by the CPS grows wider, agencies such as public institutions and critical infrastructure are collectively measuring and evaluating information security capabilities. Currently, these methods of measuring information security are a concrete method of recommendation in related standards. However, the security controls used in these methods are lacking in connectivity, causing silo effect. In order to solve this problem, there has been an attempt to study the information security management system in terms of maturity. However, to the best of our knowledge, no research has considered the specific definitions of each level that measures organizational security maturity or specific methods and criteria for constructing such levels. This study developed an information security maturity model that can measure and manage the information security capability of critical infrastructure based on information provided by an expert critical infrastructure information protection group. The proposed model is simulated using the thermal power sector in critical infrastructure of the Republic of Korea to confirm the possibility of its application to the field and derive core security processes and goals that constitute infrastructure security maturity. The findings will be useful for future research or practical application of infrastructure ISMSs.

Analyzing Weights of Certification Assessment Criteria on the G-SEED System Using the AHP Method -Focused on Certification Standards for Apartment Buildings- (계층분석법을 이용한 녹색건축 인증제도 평가항목의 중요도 분석 -공동주택 인증기준을 중심으로-)

  • Choi, Yeo Jin
    • KIEAE Journal
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    • v.13 no.6
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    • pp.113-120
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    • 2013
  • Many countries over the world have taken many discussions and endeavors on environmental improvements of energy savings and greenhouse gas emission reductions for solving global climate change problems. In Korea, pre-considerations of environment-conscious factors in buildings have been taken to be critical with new constructions and renovation markets. In this situation, the Korean Green Building Certification(KGBC) system to induce the diffusion of sustainable buildings was introduced in 2002 and developed as an improved version of the G-SEED(Green Standard for Energy and Environmental Design) system in 2013 after major revisions. This research examines the importance of assessment criteria on apartment buildings to certify green buildings using the AHP(Analytic Hierarchy Process) method and suggests a new direction on certification assessment standards from the AHP result. In order to apply the AHP method, the survey via e-mail was conducted to design staffs in domestic architectural firms. As a result, assessment criteria such as ecological environment, indoor environment, and energy & environment pollution among 7 main ones proved to be important on assessing the G-SEED system for apartment buildings, while criteria such as land use & transportation, material & resource, water circulation management, maintenance management did relatively unimportant.

Comparative Analysis on the Railway Construction Criteria with Regard to the Trans-Korea Railway Project and the Railway Modernization of DPRK (남북철도 현대화를 위한 남북한 철도건설기준 비교 분석)

  • Kim, Sang-Gyun
    • Journal of the Korean Society for Railway
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    • v.12 no.6
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    • pp.1011-1017
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    • 2009
  • In pursuit of the Trans-Korea Railway (TKR) project connecting the Korean peninsular by a rail link, it is critical that the two railway systems in ROK and DPRK are comparable in criteria and standards. Yet, there is substantial divergence of the construction criteria between the two sides, which hinders from conducting the TKR project as well as the railway modernization of DPRK. In this regard, study and comparison of the criteria are a prerequisite for mitigating the hinderance. This study investigated the laws and regulations relating to the railway technologies and construction and in particular conducted a comparative analysis of both railway systems with a focus on railway facilities such as track, structures, electric power and signaling. The results of this study will provide a useful information for the improvement of existing lines and the construction of new lines in DPRK.

Reliability analyses of a prototype soil nail wall using regression models

  • Sivakumar Babu, G.L.;Singh, Vikas Pratap
    • Geomechanics and Engineering
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    • v.2 no.2
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    • pp.71-88
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    • 2010
  • Soil nailing technique is being widely used for stabilization of vertical cuts because of its economic, environment friendly and speedy construction. Global stability and lateral displacement are the two important stability criteria for the soil nail walls. The primary objective of the present study is to evaluate soil nail wall stability criteria under the influence of in-situ soil variability. Finite element based numerical experiments are performed in accordance with the methodology of $2^3$ factorial design of experiments. Based on the analysis of the observations from numerical experiments, two regression models are developed, and used for reliability analyses of global stability and lateral displacement of the soil nail wall. A 10 m high prototype soil nail wall is considered for better understanding and to highlight the practical implications of the present study. Based on the study, lateral displacements beyond 0.10% of vertical wall height and variability of in-situ soil parameters are found to be critical from the stability criteria considerations of the soil nail wall.

Bi-Criteria Process Routing Based on COMSOAL Approach

  • Lee Sung-Youl
    • Management Science and Financial Engineering
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    • v.11 no.2
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    • pp.45-60
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    • 2005
  • This paper investigates the application of the computer method COMSOAL (Computer Method of Sequencing Operations for Assembly Lines) to the process routing (PR) problem with multiple objectives. In any computer aided process planning (CAPP) system, one of the most critical activities for manufacturing a part could be to generate the sequence that optimizes production time, production cost, machine utilization or with multiple these criteria. The COMSOAL has been adopted to find the optimum sequence of operations that optimizes two major conflicting criteria : production cost and production quality. The COMSOAL is here slightly modified to simultaneously generate and evaluate a set of possible solutions (called as population) instead of processing a solution stepwise in each iteration. The significant features of the COMSOAL include : no parameters settings needed, and a guarantee of feasible solutions. Experimental results show that COMSOAL is a simple but powerful method to quickly generate multiple feasible solutions which are as good as the ones obtained from several other well-known process routing algorithms.

A Study on Clogging and Hydraulic Properties for Drain Filters of Tunnels (터널배수재 필터의 폐색 및 수리적 특성에 관한 연구)

  • 문준석;한봉수;장연수;이두화
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.04a
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    • pp.111-115
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    • 2001
  • Durability of tunnel drains is important, because the accumulation of groundwater around the tunnel due to clogging of filter or reduction of discharge capacity of drain causes reduction of the life time of tunnel linings. In this paper, clogging and discharge capacity of drain and filter of tunnels are evaluated using a gradient ratio test and filter design criteria. The results of the gradient ratio test showed that gradient ratio(GR) is high when fine content is high in the soil samples and equivalent opening size(EOS) of filter materials is small. Measured GR was less than allowable critical gradinet ratio : 3.0, which is the clogging criteria of U.S. Army Corps of Engineers.

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Prediction for Forming Limit of Tube Warm Hydroforming Based on the Ductile Fracture Criteria (연성파괴 이론을 적용한 튜브 온간액압성형의 성형한계 예측)

  • Yi, H.K.;Moon, Y.H.;Lee, J.H.;Lee, Y.S.
    • Transactions of Materials Processing
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    • v.16 no.6
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    • pp.426-431
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    • 2007
  • Hydroformability and fracture criteria of FE analysis based on ductile fracture were investigated in warm hydroforming of A16061 tube. To evaluate the hydroformability, uni-axial tensile test and bulge test were performed at room temperature and $200^{\circ}C$. The measured flow stresses were used as input parameters for FE analysis. The damage values were calculated by FE analysis based on ductile fracture criteria at maximum radius of free bulged tubes. Damage values were compared of hexagonal shaped hydroformed parts. As a result, the formability by critical damage value for extruded tube is lower than that of full annealed tube up to 0.5.

Estimation of Structural Damage by Blasting Vibration Considering the Environmental Crack Deformation (일상 환경변화를 고려한 구조물 진동피해의 수준 평가)

  • 정지문;양형식
    • Journal of the Korean Geotechnical Society
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    • v.15 no.5
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    • pp.57-64
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    • 1999
  • In order to decide critical vibration level on structural damages induced by near blasting, deformation of existing cracks in structure was investigated and ground vibrations were measured. New criteria to evaluate blasting damage to structure are proposed considering daily deformation of cracks in structures. Results from 2 brick houses in fishing village show that new design criteria far more than current are required to cause structural damage for brick houses.

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